Cameroon is a country in Western Africa that borders the Bight of Biafra. Neighboring countries include the Central African Republic, Chad, the Republic of the Congo, Equatorial Guinea, Gabon, and Nigeria. The geography of Cameroon is diverse with coastal plains in the southwest, plateau in the center, mountains in the west, and plains in the north. The government system is a multiparty presidential regime republic; the chief of state is the president, and the head of government is the prime minister. Cameroon has a mixed economic system which includes a variety of private freedom, combined with centralized economic planning and government regulation. Cameroon is a member of the Economic Community of Central African States (ECCAS).